Posterior Hip Muscles Flashcards
Major Connective tissue and ligaments
• Obturator membrane covers the obturator foramen.
- The obturator canal is a small opening in the membrane. The obturator nerve travels through this canal from the pelvic
cavity to the anterior/medial thigh.
• These two ligaments serve as important landmarks and muscle attachment sites.
- Interosseous sacro-iliac ligament (deep): as its name suggests, it secures the sacrum and ilium.
- Posterior sacro-iliac ligament: a larger, more superficial ligament with fibers that run in multiple directions to secure the
pelvic bones.
- Sacro-spinous ligament - runs from the sacrum to the ischial spine.
- Sacro-tuberous ligament - runs from the sacrum to the ischial tuberosity.
• Sciatic notch
- The interosseous sacroiliac and posterior sacroiliac ligaments pass over the sciatic notch, converting it into foramina:
The greater sciatic foramen, superior to the sacrospinous ligament. The lesser sciatic foramen, inferior to the ligament.
These foramina provide entry and exit points to the pelvis and perineum.
Superficial muscles of the posterior hip
Gluteus minimus
Gluteus medius
Tensor fascia latae
Gluteus maximus
Gluteus minimus
the smallest and deepest of the gluteal muscles.
- Arises from the ilium, between the anterior and inferior gluteal lines, and inserts on the greater trochanter of the femur.
Gluteus medius
- Arises superior to gluteus minimus, between the anterior and posterior gluteal lines, and also inserts on the greater
trochanter of the femur. - Abduction, IR
- Sup. gluteal N
Tensor fascia latae
a small muscle that arises from the iliac crest and anterior superior iliac spine; this muscle is also
visible in anterior and lateral views.
- The fascia that covers this muscle extends inferiorly as the iliotibial band, which attaches to the tibia (not shown); thus,
the iliotibial band, aka, the IT band or tract, stabilizes the knee
Gluteus maximus
the largest muscle in the hip
- Arises from the posterior ilium and sacrum (specifically, from the sacro-tuberous ligament) and extends inferiorly and
laterally; the deeper fibers of this thick muscle attach to the gluteal tuberosity of the femur, whereas the more superficial
and anterior fibers attach along the iliotibial band
Deep muscles of posterior hip
Quadratus femoris
Inferior gemellus
Obturator internus
Superior Gemellus
Quadratus femoris
- Arises from the ischial tuberosity and inserts on the intertrochanteric crest of the femur.
As its name suggests, this is a rectangular (“quadratic”) muscle; “femoris” refers to the femur – be careful not to confuse
this muscle with rectus femoris, a long muscle in the anterior thigh. - ER
- N to quad femoris
Inferior gemellus
- Arises from the ischial tuberosity and inserts on the greater trochanter of the femur.
Obturator internus
Arises from the obturator membrane and the ischiopubic rami and inserts on the greater trochanter via a thin tendon.
Superior gemellus
Arises from the ischial spine and inserts on the greater trochanter
Triceps coxae
The gemelli and obturator internus muscles are so closely related in structure and function that they are sometimes
referred to as the “triceps coxae.”
Pathway of sciatic nerve
• The sciatic nerve exits the pelvis via the greater sciatic foramen, travels deep to piriformis, then over the rest of the
lateral rotators to the thigh.
- This anatomical relationship can be problematic, as the piriformis muscle can irritate or compress the sciatic nerve,
resulting in piriformis syndrome, which is characterized by pain, tingling, or numbness along the posterior leg and into
the foot.
- Intermuscular injections are given in the gluteal muscles in the superior lateral quadrant of the hip to avoid the sciatic
nerve.
Sciatic foramina and contents
The greater sciatic foramen* is divided into superior and inferior portions by the piriformis muscle.
- Above the piriformis: the superior gluteal vessels and nerve travel to the glutes.
- Below the piriformis, several neurovascular structures pass: sciatic nerve, inferior gluteal vessels and nerve, internal
pudendal vessels and nerve, posterior femoral cutaneous nerve and the nerve to obturator internus & superior gemellus
muscles, and, the nerve to quadratus femoris and inferior gemellus muscles.
Through the lesser sciatic foramen*: the tendon for obturator internus muscle exits to the greater trochanter, and, the
pudendal nerve and vessels pass back from the gluteal region to the perineal region.
